1. Field of the Invention:
The present invention relates to a device for cooling a printer head used, for example, in dot-impact printers.
2. Description of the Related Art:
There are known various serial dot-impact printers including a printer head reciprocally movable across a paper, sheet for printing thereon a line of characters each composed of a matrix of dots. The printer head is provided with a bundle of needles or pins each corresponding to one dot and selectively projectable by the energization of an electromagnetic coil to force a portion of an ink ribbon against the paper sheet, thus printing characters on the paper sheet.
Since the temperature of the printer head is increased during a repeated energization and de-energization of the electromagnetic coils, a cooling device in the form of radiator fins is provided around the printer head for radiating heat and thus cooling the printer head by means of airstreams established around the printer head during the reciprocating motion thereof.
Such an air-cooling type of cooling device is however insufficient to radiate a great amount of heat which is produced, for instance, when all of the pins are driven by the electromagnetic coils to print boldfaced characters or when the printer head is continuously operated for a long period of time. With this insufficient heat radiation, the electromagnetic coils are likely to be damaged or broken due to overheating, resulting in an operation failure or malfunction of the printer head. Thus, the conventional air-cooled printer head has a relatively short service life.
Yet, in view of a recent tendency in the dot-impact printers toward a high-speed operation in which a great amount of heat is produced from the printer head, there is a keen demand for a cooling device which is sufficient to cool the printer head of such a high-speed printer.